1. Field of the Invention
This invention relates to a bar code printer, particularly to an automatic printing apparatus of bar code on a label to be adhered to articles sold in department stores or supermarkets. More specifically, this invention relates to an improved bar code printer comprising an input unit feeding prescribed input data as input signals in a prescribed form into a signal control system, the signal control system operating a bar code printing system and an indicating system according to the input signals, the bar code printing system and the indicating system.
2. Description of the Prior Art
First, the input unit of the bar code printer will be discussed.
Conventional bar code printers are classified into two types, i.e. a desk type bar code printer and a weighing bar code printer. The desk type bar code printer applies to articles without the necessity of weighing, such as processed foods or groceries, and the weighing bar code printer applies to articles to be weighed, such as meat, raw fish, vegetables or fruits. Each of two types can be used only for its sole purpose, either as a desk type bar code printer or as a weighing bar code printer.
In the weighing bar code printer issuing the weight indicating label with bar code, a disadvantage occurs in that two identical labels must be issued for articles which cannot be turned sideways or upside down, such as dished slices of raw fish. In such articles, the weight indicating label must be adhered to the front surface at a readily viewable portion, while the bar code label must be adhered to a flat surface so as to secure the automatic reading using a stationary scanner, that is, the bar code label in such an article must be adhered inevitably to the rear surface. As a result, the two identical labels are required. Accordingly, it is preferable to print the weight indicating label and the bar code label separately for articles such as dished slices of raw fish. For this purpose, one type of bar code printer may be used in which a weight indicating label printer is accompanied by a bar code printer. However, this type cannot be used as a desk type bar code printer, and installation of a further desk type bar code printer in a store may take much space.
The input unit feeds print data to the signal control system by a keying operation according to the markig code. Of various types of the marking code system, the most suitable type for articles to be marked is selected from the code contrast table. The code contrast table of the JAN code type, as an example, is as follows. JAN code corresponds to UPC code in the U.S.A.
______________________________________ Code System Flag ______________________________________ JAN13NONPLU 02 *I1 I2 I3 I4 I5 P/C P1 P2 P3 P4 C/D type JAN 13 PLU type 04 I1 I2 I3 I4 I5 I6 I7 I8 I9 I10 C/D JAN8NONPLU 2 I1 I2 P1 P2 P3 P4 C/D type JAN 8 PLU type 0 I1 I2 I3 I4 I5 I6 C/D others -- -- ______________________________________ *I.sub.n : item code, P.sub.n : price code, P/C : price check digit, C/D module check digit
In the above table, flag code designates countries or types of in-store marking code, maker code designates makers of articles, item code designates items set by makers or stores under a definite standard, and price code designates prices of articles.
In inputting the price data, difference of numerals between the previous and new input data in even one column requires the inputting of all print data again although the same type of marking code is used.
In the pricing process of various types of articles in a store, therefore, all print data must be input from the beginning per article. This requires much time for the pricing process, and causes a false input of print data.
If the pricing process is carried out per section, articles of the same section are treated during a certain time. In the marking code of the JAN13NONPLU type, for example, only the lower two columns of item code and price code vary, and flag code and residual columns of item code are common in the section. Therefore, the marking may be divided into a fixed part of common numerals and a variable part of different numerals.
Any of the code systems selected from the above contrast table follows a rule: flag code at the top (left end), item code, price check digit, price code and module check digit must be registered in sequence. As shown in the code contrast table, however, the various types of code systems are different in the number of columns of item code. Some code systems are different in that some are without price check digit or a price code. Since it is difficult for an operator to memorize all types of code systems correctly and it is liable to cause false input, use of the code contrast table is essential. Accordingly, input operation of the bar code data is not efficient.
If position of flag code and check digital or existence of check digit can be known, residual item code and price code may be easily registered, which eliminates the false input of the bar code data and improves the efficiency of the input operation.
In a conventional manner, numerals in check digit are manually calculated according to a prescribed calculation formula, and the calculated numerals are registered in check digit positions determined by the code system. The calculation requires much time and reduces the working efficiency in the input operation of the bar code data. Moreover the manual calculation is liable to cause a mistake.
In the labels printed by the bar code printer, such as labels by in-store marking, the bar code comprising flag code, item code, price check digit and price code is printed as above described. In a conventional manner, the consumer's price is not indicated on the same label with the bar code, but on a separate price label. Or otherwise, even if the bar code and consumer's price are indicated on the same label, two sorts of price data, i.e. that in the bar code and that for displaying, are set and printed using a desk labeller or a hand labeller. Therefore, the setting operation must be carried out twice and takes much time, thereby it is liable to cause a mistake of setting, resulting in reduction of working efficiency.
Next a bar code printing system will be discussed.
In a conventional manner, since bar code is optically read out by a stationary scanner or pen reader, it must be printed accurately. Requirements of the accuracy are as follows:
(1) Thickness of bars and spacing between bars must be correct. PA1 (2) Bars must be in parallel with each other. PA1 (3) Width of each bar must be uniform throughout the length. PA1 (4) Bar edge must be a sharp line. PA1 (5) Bar must be free from defect or contamination.
Means for printing bar codes on a label are classified into the drum inpact method and the wire dot method. In the drum impact method, bars set to a drum are struck through a ribbon onto a label fixed to a prescribed position of the base so as to carry out printing, therefore the method has disadvantages in that spacing between bars is liable not to be uniform since the structural reason and printing of correct bar code is difficult, a ribbon, ink or the like must be supplied corresponding to dissipation, and bars are susceptible to defect or contamination. In the wire dot method, a head composed of a suitable number of aligned wires is opposed through a ribbon to a printing surface of a label conveyed at a prescribed constant speed, and only wires with circular cross-section, set by a controller, are struck at regular intervals onto the printing surface during the label conveying so as to carry out printing. Therefore, the method had disadvantages in that the edge of the printed bar was uneven, non-uniformity of the label conveying or escape of the label prevented the correct bar code printing, and the printing speed was slow.
Accordingly, if the bar code, produced by the above mentioned methods, is read out by a stationary scanner or a pen reader, the reading is susceptible to mistake.
A bar code label may be provided with indication of trade marks or store names. In order to produce a bar code with marks, trade marks or store names are previously printed on labels, and the printed labels are charged in a printer for the bar code printing. Adoption of this process means that the conventional printer cannot print trade marks of store names. It also cannot produce a colorful printing with a combination of different colors.
Accordingly, printing cost of the above mentioned label is higher than that of white paper to be printed with only bar code by separate cost for printing trade marks orr store names.
Of course, labels with trade marks or store names can be used only in the specific store. This is also inconvenient.